Improvement in the manufacture of soap



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UNITED STATES GHAnLEs LEHMANN, or New roux, n. Y.

IMPROVEMENT IN THE MANUFACTURE OFSOAP.

. Specification forming part of Letters Patent No. 158,720, dated January 152, 1875; application'filed November 28, 1874'.

To all whom it may concern:

,Be it known that 1, CHARLES LEHMANN, of the city, county, and State of New York, have invented a certain new and useful Improve- .ment in the Manufacture of Soap, of which the following is a specification:

This invention consists in heating tallow or grease with a suitable quantity of rosin in a separate vessel, and adding to this mass, while the same is hot, caustic lye of from 30 to 36 portions is put in a kettle; then caustic-soda lye, of the strength of 15 to 20.Baum, is added; then the mixture is boiled until saponification takes place, and finally an additional quantity of soda-lye is added, so as tovrais e the boiling mass to the required strength. By this process a large surplus of water is mixed with the soap, andstrong salt-lye is added for the purpose of effecting a separation of the water from the sea The water thus separated contains a quantity of caustic lye, whereby its strength becomes that of the soap floating on the liquid; and, furthermore, the water also contains the saltlye, the glycerime, and other ingredients,

' which previously had been chemically combined with the fat, but which at this stage of the process form parts of the waste or mother lyc., After leaving the mass atrest fon several hours this mother-lye is drawn off and thrown away; then a fresh quantity of causticsoda lye, of from 12 to 14 Baum, is added to the soap-stock in the kettle; the mass is fresh quantity of salt-lye is added; the mass is permitted to rest; then the mother-lye is drawn off and again thrown away. One full day at least is needed foreach of these operations, and it requires five days in succession till the soap is finished. After that the soap'has to rest in the kettle, for cooling and settling the socalled nigr. For cooling, three or four days are required; then the soap is taken out of the kettle and mixed with various ingredients, such as sal-soda or silicate of of the same grade as.

soda; it stands for six to eight days, until it is hard ened and ready for cutting. The time required for the whole operation averages seventeen days. During this time steam or fire is required for six days, and, furthermore, a'large quantity of caustic soda and all the salt re (mired in the separation are lost. l

By the process which I have invented not only much time is saved, but the waste of soda-lye is avoided.

I charge the kettle with a quantity of tallow or grease, and add thereto a quantity of rosin, according to the desired quality of the product; then 1 heat, either by means of steam or by a direct fire, until the mass is entirely dissolved. If a direct fire used, a quantity 'of water must be added to the grease. After the mass has been melted it is allowed to set tie, while it is kept as hot as possible.

The caustic-soda lye which I use is of the strength of from 30 to 36 Baum. This strong lye is heated to the boiling-point in aseparate kettle, and then a certain quantity of the fat and the rosin, prepared as above stated, is mixed with a corresponding quantity of the boiling lye in a third vessel, and in a few minutes a chemical reaction will commence, whereby the heat of the mixture still further in creases, and a perfect saponification takes place at once. The soap is now ready to be mixed with sal-soda, silicate of soda,or other suitable ingredients, the same as long boiled soap.

By this process the saponification is more intensive and more accurate than it is when the fat and a weak lye are boiled together, be-

cause the heat, in consequence of the chemical reaction, rises rapidly above 212; and, furthermore, no soda-lye is lost or wasted in my process, no salt-lye is requisite to .eii'ect any separation of water from the soap, and'it requires no particular skill to effect the s'aponification. p

In the manufacture of boiled soap with weak lye it is necessary to employ-practical men, and even they fail sometimes toetfect a correct saponification, and it sometimes hap' pens that the soap is spoiled; and, since the result can only be examined after the soap is cold enough to be cut, it happens frequently then the soap is put in frames. in which fuel.

that the whole mass of soap must be boiled over at a considerable loss of time, labor, and

By my process a correct saponification'is insured, and the time for manufacturing soap is shortened more than one-half, and a manufacturer who has the facilities to manufacture twenty thousand pounds of soap by the old process can produce sixty thousand pounds by, my process in half the time, with less expenditure, and with a great saving in wages. In my process the fat, on being heated in a separate "essel, is freed from impurities, which latter settle down, together with the water which is added to the fat, when the kettle is exposed to the direct action of the fire, or

which results from the condensation of the steam, in case such is used for heating; and, as the refined fat free from water is mixed with the strong heated lye in a separate ves- -fication is effected without anywaste of lye,

substantially in the manner set forth.

In testimony that I claim the foregoing I hay'ehereunto set my hand.

OHA RLES LEHMANN. Witnesses:

J. VAN SANTVOORD, W. HAUFF. 

